This invention relates to a vehicle trim panel assembly having an electrical circuit integrally molded into grooves. The subject invention also relates to the method of fabricating the trim panel with the electrical circuit.
Vehicles typically have a number of trim panels mounted to different interior surfaces to present a pleasing appearance. One common type of trim panel is a door trim panel mounted to the interior surface of a door assembly. Typically, vehicle door assemblies include spaced apart inner and outer panels defining a cavity for mounting a window, window regulator, speaker, and other electrical devices. These devices are installed inside the door cavity through a plurality of access openings provided in the door inner panel.
The door trim panel conceals this interior surface of the door. The door trim panel is conventionally formed of a rigid panel, such as molded plastic or pressed hardboard, covered with a flexible decorative trim material such as cloth, vinyl, leather and/or carpeting. The door trim panel creates a pleasing appearance to the occupant, and is attached to the door by suitable fasteners.
The door trim panel also often supports a number of electrical components. These components include lights, window controls, rear view mirror controls, seat adjustment controls, and speakers. Each of these electrical components requires an individual wiring connector and power supply lead wires. The power supply lead wires for all the electrical components are typically bundled together to create what is commonly called a wiring harness. The wiring harness is often affixed to the trim panel or to the door to eliminate movement of the wires during operating conditions. As can be appreciated, the mounting and wiring of these electrical components is labor intensive and requires a number of connectors and other electrical parts.
Solutions to this problem have been contemplated by the prior art. Specifically, the prior art has proposed the power supply lead wires be mounted, molded, etched, printed, or otherwise affixed to a separate rigid board. The rigid board is in turn mounted in some fashion to either the trim panel or the door or both. Hence, in these proposals, the door assembly includes the door itself, a rigid board, and then the trim panel. In another solution proposed by the prior art, the interior surface of the trim panel includes at least one groove interconnecting one electrical connector to another electrical connector. A binding agent and an electrically conductive material are integrally deposited and adhered to the groove to define an electrical circuit.
These proposals, however, likewise have a number of deficiencies. The solution of incorporating the circuits into a separate board still requires a significant amount of manual labor to mount the wires to the board, mount the connectors to the board, and then mount the board itself to either the trim panel or the door. Further, additional connectors must be mounted on the board to electrically connect the connectors from the door to the connectors on the trim panel. The solution of a trim panel with an integrally molded electrical circuit requires a binding agent such as liquid polyurethane to be applied within the groove. This solution requires specialized equipment and additional labor to apply the binding agent.
Accordingly, it can be seen that it would be advantageous if there could be developed a method of forming an electrical circuit on a surface of a substrate wherein the method is easier and more economical than prior art methods.
It would also be advantageous if there could be developed a method of forming an electrical circuit within a groove formed on a surface of a substrate wherein the binding agent is eliminated.
Further, it would be advantageous if there could be developed a method of forming an electrical circuit within a groove formed on a surface of a substrate wherein the bottom surface of the groove is configured to facilitate adherence of an electrically conductive material.
The above objects as well as other objects not specifically enumerated are achieved by a method of forming an electrical circuit on a surface of a substrate. The method includes providing a substrate having a surface with at least one groove formed therein, the groove having a bottom textured surface; and applying an electrically conductive material onto the bottom textured surface of the groove.
In one embodiment of the invention, the bottom textured surface of the grooves have an irregular, non-smooth surface with a random grainy pattern. A thin layer of zinc and copper are then applied to the textured surface of the groove.
Preferably, the groove is integrally formed into the surface of the substrate during the manufacture of the substrate, and the bottom textured surface has a roughness such as sandpaper having a roughness within the range of from about 16-grit to about 50-grit sandpaper. The layer of zinc and copper preferably include at least one layer of zinc within the range of from about 0.02 millimeters to about 0.10 millimeters thick, and at least one layer of copper within the range of from about 0.10 millimeters to about 0.50 millimeters thick.